In the last post, we discussed Project Scope Management and the five project management processes that make up the knowledge area. In continuation of our series, we will examine another project management knowledge area that is important for the PMP exam – Project Time Management.
Project time management is one of the most critical aspects of managing a project. Indeed, if we had infinite time to deliver our projects, the success rates of projects would greatly increase. But then, if projects had infinite time, then they would no longer be called projects. Going by its definition, “a project is a temporary endeavor undertaken to create a unique product, service or result.” This key attribute of projects (that they are temporary) forms an important part of the triple constraint in project management.
PMP Training – Resources (Intense)
See more information on the triple constraint here:
In this post, we will examine the six (6) processes that are involved in project time management, paying attention to inputs, tools and techniques, and outputs of these processes. The six processes are:
- Define activities
- Sequence Activities
- Estimate Activity Resource
- Estimate Activity Duration
- Develop Schedule
- Control Schedule
The first five processes are usually performed in the planning phase of the project, while the sixth process (control schedule) is performed in the monitoring and controlling phase of a project. Now let’s examine each of these processes.
The activities definition process has already begun with the work breakdown structure process in scope management (See previous post). The scope baseline that was created is used as a reference here. Sometimes, a work package might be further decomposed into smaller activities. As a project manager, you’re required to have expert judgment and insight from other concluded projects in defining activities properly. The outputs of this process are the list of activities, their attributes, and a milestone list.
A milestone is a critical point in project management because it usually indicates the completion of a key deliverable. It is also important because sometimes, project funds can be tied to the achievement of a milestone, for example, the development of a beta product in software project management or the completion of the foundation in construction project management.
The activities sequence process involves using various tools and techniques to organize the activities into a sequence. The major inputs to this process are the outputs from the activity definition process (activity list, activity attributes and milestones). You should also pay attention to the project scope statement while doing this. Some of the tools and techniques involved in sequencing activities include:
- Precedence Diagramming Method: PDM is used to show the order of tasks in a project to determine the critical path of the project. In this method, activities are represented in boxes, called nodes, and arrows are used to show the relationships between these activities. A precedence diagram can be developed using software or using a simple hand-sketch. An example of a precedence diagram using Microsoft project software is shown below:
- Another example of a simpler PDM is shown below:There are four kinds of relationships that can occur between activities:
- Finish to start: This is the easiest. Activity A must end before activity B can start. You need to build the walls before you can paint them.
- Start to finish: Activity A must have started before activity B can finish. This is the least common.
- Finish to finish: Activity A must finish before Activity B can finish.
- Start to start: Activity A must start before activity B can be started.
- Dependency determination: As a project manager, you must be able to determine if an activity is dependent on the other. Generally, there are three kinds of dependencies:
- Mandatory dependencies: These are dependencies that are either explicitly stipulated in the contract or inherent in the nature of the project. For example, you can only test a module or prototype after it has been developed. These kinds of dependencies are also called hard logic.
- Discretionary dependencies: These dependencies are at the discretion of the project manager and the team. For instance, we can decide to paint building A before painting building B. These kinds of dependencies are also called soft logic. As a project manager, you should ensure that they are documented properly.
- External Dependencies: These dependencies are outside the control of the project team. For instance, with pharmaceutical or biomedical projects, external regulations and approvals might be required before further development of the product can be carried out.
- Applying leads and lags: A lead allows you to start an activity before its normal schedule time. For instance, if you can start marketing a product one month before its development is concluded, you have a finish to start relationship with a one month lead. On the other hand, a lag imposes a delay on an activity that should have started. For instance, you might require that you have to wait for one week after conducting the polls before you begin to collate the results.
The major output of the sequence activities process is the schedule network diagram of the project. This is a diagram that represents the activities required to complete the project and the relationships between the activities.
The third process required for project time management is activity resource estimation. This process involves determining the resources required to execute the activities that have been defined in the activities definition process. You will need the activity list and attributes as well as the resource calendars (documents that show which resources are available at a particular time) in order to create a realistic estimate.
As a project manager, you will require expert opinion in order to determine the resources you need on a project. You also need to explore alternatives, such as considering the impact of using a machine or software instead of performing a task manually. You should also use information from past projects that are available to you in order to make an informed decision. You might also decide to use available public information such as industry rates for renting equipment or hiring resources. If all these prove too difficult, then use the work breakdown structure (or the activity list) as a step by step guide in your resource estimation.
The outputs of the resource estimation process are the resource requirement document and a resource breakdown showing the type (level of skill required) and categories (labor, material, equipment and supplies) of resources that you need to deliver the project.
Estimate Activity Duration
The fourth process in project Time management is the estimation of activity duration. Since you have identified the project activities and the resources needed to achieve them, the next phase is to determine the amount of time required to perform these activities. The inputs of this process are the outputs from the activity definition and resource estimation processes. This is logical since you must have determined the activities and resources before you can determine the amount of time you need to perform them.
By now, you should be tired of hearing about the triple constraint (scope, time and cost) but this three-headed demon is the reason why most projects fail. As a project manager, you should be aware of the estimation techniques that are available to you and what they entail. Some of the estimation techniques include:
- The first kind of estimation is analogous estimation. This involves using information about analogues, which are similar projects that have occurred in the past. You can say, for example, that based on previous experience, it takes about 6 months to complete a primary school building project. Although analogous estimations are faster and less costly, they are usually less accurate because they do not factor in the unique differences of each project. Analogous estimations are usually a good reference point to begin your estimations.
- Parametric estimation involves using historical data as a basis for estimation. For example, if it takes a painter one day to paint a wall, then it would take the painter about four days to paint all the four walls of a room. The accuracy of parametric estimates depends on the accuracy of the historical data underlying the estimate.
- Three point estimates involve using the optimistic, most likely, and pessimistic values to compute an estimate. The estimation is done by calculating the PERT (Program Evaluation and Review Technique) average of the values. The PERT average is calculated by:(o + 4m + p) / 6Where o is optimistic, m is most likely and p is pessimistic.If it would most likely take ten days to perform a task and six days in the best case but 18 days in the worst case, the PERT average would be:(6 + 4*10 + 18)/6 = 10.67 days which is approximately 11 days.The three point estimation is usually more accurate than the other forms of estimations because the risks factors are considered in this estimation.
Along with these estimation tools, you should employ the opinion of experts and ensure you create a contingency reserve in your estimates to cater for unforeseen circumstances. As you move along in the project, you can adjust your reserves based on your performance. Remember that all your reserves must be properly documented for proper communication with your team and other stakeholders.
The output of the duration estimation process is the activity duration estimates. The estimates usually show a percentage of risk such as, “There is a 90% probability that the project will not exceed 90 days.”
In the next post, we will examine the remaining processes while paying attention to important concepts like critical path calculations, floats and schedule management techniques. As usual, if you have any questions/thoughts, please feel free to use the comments section. Thank you for reading and I hope to see you soon!